Hilary Duff has been an open book since the birth of her son, Luca, on March 20.

Recently Hilary shared a story about how she kept her newborn babies belly button stump.

The wife of NHL’s, Mike Comrie, was asked about the joys of motherhood and said one of the most exciting moments of Luca’s life was when the remainder of his umbilical cord fell off.

Duff told People Magazine, "I wanted to keep it but my husband was like, 'No, that's gross, you can't keep it!' I'm like, 'I'm totally keeping it', and I secretly kept it. “

"But now it's not a secret anymore. It's in a Ziploc bag in the back of my makeup drawer. Luca's going to think I'm a freak!"

The former Lizzie McGuire star just recently signed on to be the new spokesperson for Johnson's Baby Cares initiative.